On Mon, 08 May 2006 11:06:11 GMT, Peggie Hall
wrote:

Mic wrote:

On Sun, 07 May 2006 23:32:14 GMT, Peggie Hall
wrote:


krj wrote:


How many days will a 13 gallon tank last for 2 people before having pump
it out?


Here's the math you need to know about how long it will take to fill up
any size tank:

The average adult uses the toilet 5x/day...average flush is .6 gal. So
each person continuously aboard will put about 3 gal/day into the tank.

But if you had a Therford with a 5 gallon holding the average use per
flush is about 53 uses till full.

That would be true of any similar size portapotty, whether portable or a
permanently installed "pumpable" version. However, while 53 flushes may
SEEM like a LOT more, when you remember that two people = 10
flushes/day, it's only an average of about 5 days vs 3 with a manual
toilet if you know how to use the "dry" mode to conserve flush water.

--
Peggie

http://www.thetford.com/portable_main.cfm

Porta Potti 585
62 Avg. # Flushes

53 was a wild guess the 585 model avg. 62

It seems that many prefer this option to the standard config. on a
retro fit for thoses vessels less than 28ft and for casual boating
seems to make sense, practically and cost wise. Although in
outfitting an ocean going vessel this option is not desirable in heavy
seas?

The volume created using the conventional system is considerably more
per use than the thetford system as are the maintenance issues and
cost.

http://www.pocketcruisers.com/art_portapotti.html
In Praise of the Humble "Porta Potti"
By Buzz Pratt, Pocket Cruisers

Which system would you advise on and why? I guess it would relate to
the size of the vessel as well.

Mic wrote:
53 was a wild guess the 585 model avg. 62

That's a WEE bit of a stretch...50 is actually closer to accurate.

It seems that many prefer this option to the standard config. on a
retro fit for thoses vessels less than 28ft and for casual boating
seems to make sense, practically and cost wise.

Yep...and I often recommend a self-contained system for smaller boats.
No moving parts to maintain, no plumbing except a vent and pumpout
line...and with the addition of a y-valve and pump, even be dumped at
sea. No tank occupying a major portion of valuable storage...and it
costs a lot less.

Although in
outfitting an ocean going vessel this option is not desirable in heavy
seas?

There's no more problem with it than any other tank in heavy seas
....the tank is sealed, so the contents won't end up all over the boat.

The volume created using the conventional system is considerably more
per use than the thetford system as are the maintenance issues and
cost.

You keep referring to it as "the Thetford system"...as if they're the
only mfr who offers a self-contained pumpable/dumpable system. The
SeaLand 965 MSD is 5.6 gal system...and other portapotty that has a
model name or # that includes an "MSD" designation. Actually just about
any portapotty COULD be converted by simply installing a vent and
pumpout fitting in the tank...'cuz that's the only difference between a
portable and pumpable portapotty. The "MSD" versions just already have
'em installed.

Which system would you advise on and why? I guess it would relate to
the size of the vessel as well.

Very definitely related to the size of the vessel...but as much to meet
buyers' expectations as practicality. A portapotty is a good choice for
any vessel under about 26-28'...but today, the owners of larger boats
want a "real" marine toilet, not a "camper" toilet. Over 30'--often even
smaller--they have to have the push button convenience of electric...as
the size of the boat increases, the toilet also has to be increasingly
closer to something "just like the one at home." So it's not just
practicality that determines the "right" toilet for any boat, but human
emotional needs and a toilet that fits their image of the "right" one
for their boat. Even small boat owners..you'd be amazed at how many
owners of 24-26' sailboats cannot be talked out of replacing a perfectly
good self-contained system with a "real" toilet and holding tank.


--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

On Mon, 08 May 2006 18:02:10 GMT, Peggie Hall
wrote:

Mic wrote:
53 was a wild guess the 585 model avg. 62

That's a WEE bit of a stretch...50 is actually closer to accurate.

It seems that many prefer this option to the standard config. on a
retro fit for thoses vessels less than 28ft and for casual boating
seems to make sense, practically and cost wise.

Yep...and I often recommend a self-contained system for smaller boats.
No moving parts to maintain, no plumbing except a vent and pumpout
line...and with the addition of a y-valve and pump, even be dumped at
sea. No tank occupying a major portion of valuable storage...and it
costs a lot less.

Although in
outfitting an ocean going vessel this option is not desirable in heavy
seas?

There's no more problem with it than any other tank in heavy seas
...the tank is sealed, so the contents won't end up all over the boat.

Actually the comment regarding the self contained system came from an
article regarding blue water boats, but it did not state the issue
with this system. I would think that the difference is that when
flushing the self-contained unit the stored effluent becomes opened
abeit through about a 3inch diameter, whereas the separate holding is
plumbed to. So if the boat happens to come off the top of a wave at
the wrong moment and while flushing....

I think that those, especially on smaller boat that have had issues
with their systems opt for the self-contained units. Even to the
extent of saying that the self-contained thetford unit was a
preferrable feature in one instance when selling the boat.



The volume created using the conventional system is considerably more
per use than the thetford system as are the maintenance issues and
cost.

You keep referring to it as "the Thetford system"...as if they're the
only mfr who offers a self-contained pumpable/dumpable system. The
SeaLand 965 MSD is 5.6 gal system...and other portapotty that has a
model name or # that includes an "MSD" designation. Actually just about
any portapotty COULD be converted by simply installing a vent and
pumpout fitting in the tank...'cuz that's the only difference between a
portable and pumpable portapotty. The "MSD" versions just already have
'em installed.

A better description would have been "self-contained" .

Which system would you advise on and why? I guess it would relate to
the size of the vessel as well.

Very definitely related to the size of the vessel...but as much to meet
buyers' expectations as practicality. A portapotty is a good choice for
any vessel under about 26-28'...but today, the owners of larger boats
want a "real" marine toilet, not a "camper" toilet. Over 30'--often even
smaller--they have to have the push button convenience of electric...as
the size of the boat increases, the toilet also has to be increasingly
closer to something "just like the one at home." So it's not just
practicality that determines the "right" toilet for any boat, but human
emotional needs and a toilet that fits their image of the "right" one
for their boat. Even small boat owners..you'd be amazed at how many
owners of 24-26' sailboats cannot be talked out of replacing a perfectly
good self-contained system with a "real" toilet and holding tank.

I would think that it comes from their maintanence experiences.

http://www.tendervittles.net/logs/feb2006/022106.html
"Sewage Dilemmas or She Who Will be Known as the Toilet Slayer
February 21, 2006"

The above is a link to one of the many...such issues.